fix memory abuse in internalization in inc-sat-solver

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

src/tactic/portfolio/bounded_int2bv_solver.cpp

@@ -303,6 +303,7 @@ private:
             }
         }
         m_assertions.reset();
+        m_rewriter.reset();
     }
 };